U.S. sources have told CNN that they have prepared charges against Julian Assange, the Australian whistleblower who founded WikiLeaks.

The U.S. Justice Department has been investigating Assange since at least 2010, when WikiLeaks published thousands of stolen U.S. security files.

Last week in a speech in Washington, D.C., CIA Director Mike Pompeo said WikiLeaks directed a U.S. Army intelligence analyst in 2010 to intercept “specific secret information” that “overwhelmingly focuses on the United States.”

The Washington Post reports that prosecutors in the Justice Department have been drafting a memo considering charges against people connected with WikiLeaks. But the Post reports that any charges against those people would need approval from the highest levels of the Justice Department.

U.S. intelligence agencies say Russia used WikiLeaks to publish emails by former presidential candidate Hillary Clinton in the run-up to last year’s presidential election.

Hackers working for Russia are believed to have gotten into the accounts of officials of the Clinton campaign and the Democratic National Committee and published their emails on WikiLeaks, in order to tamper with the election’s outcome.

“It’s time to call out WikiLeaks for what it really is,” Pompeo said. “A nonstate hostile intelligence service often abetted by state actors like Russia.”

‘Step up our efforts’

U.S. Attorney General Jeff Sessions said Thursday at a news conference that Assange’s arrest is a priority for the Trump administration.

“We’ve already begun to step up our efforts and whenever a case can be made, we will seek to put some people in jail,” he said.

Assange’s lawyer, however, told CNN that he has not heard from the Justice Department about any charges against his client. “They’ve been unwilling to have any discussion at all, despite our repeated requests that they let us know what Mr. Assange’s status is in any pending investigations,” Barry Pollack said.

Pollack said WikiLeaks should be treated the same as other news outlets, such as The Washington Post and New York Times, which routinely publish stories based on classified information. His position echoes the stance taken by the Obama administration, which elected not to prosecute WikiLeaks.

Officials in the Trump administration indicated early on that they might re-examine the issue, which was never formally closed.

Assange is wanted on rape charges in Sweden, but has been granted asylum by the South American nation of Ecuador. He has been living since 2012 in the Ecuadorian Embassy in London to avoid arrest and extradition.

The Post on April 11 published an opinion piece by Assange that said, “Quite simply, our motive is identical to that claimed by the New York Times and the Post — to publish newsworthy content.

“Consistent with the U.S. Constitution, we publish material that we can confirm to be true, irrespective of whether sources came by that truth legally or have the right to release it to the media,” he added.